A hollow shaft motor test loading mechanism

Abstract

The application discloses a hollow shaft motor test loading mechanism, which comprises an extension shaft fixedly connected with the outer end of a motor shaft and a torque device for applying downward pressure to the motor shaft through the extension shaft. A support stress point and a downward pressure stress point are arranged at the front end and the rear end of the extension shaft respectively. The torque device provides upward support force F0 and downward pressure F1 to the support stress point and the downward pressure stress point respectively. The size of the support force F0 and the downward pressure F1 and the ratio between the two are adjusted, so that the front end bearing and the rear end bearing of the motor shaft in the motor bear loads exceeding the minimum load. The application has the advantages that the loads of the front end bearing and the rear end bearing are balanced and increased, the rolling unit can rotate with the rotation of the motor shaft, the friction between the rolling unit and the inner ring and the outer ring is rolling friction, the occurrence of sliding friction is avoided, the front end bearing and the rear end bearing are not damaged in the hollow shaft motor test process, and the structure is simple, reasonable and easy to operate.

Description

Technical Field

[0001] This invention relates to a hollow shaft motor test loading mechanism, belonging to the field of motor testing tooling technology. Background Technology

[0002] The minimum load of a bearing refers to the minimum load that a bearing must withstand to ensure its normal operation and protect it from damage. This minimum load is crucial for the normal operation of the bearing because it ensures that the rolling elements inside the bearing receive the necessary support and lubrication during rotation, allowing all rolling elements to undergo rolling friction evenly. This prevents wear caused by prolonged unlubricated friction in certain areas of the rolling elements, thus maintaining the bearing's performance and lifespan.

[0003] The mechanism by which bearings are damaged when subjected to loads below minimum is as follows: Due to the inherent frictional resistance between the axially arranged rolling elements and the cage, as well as between the inner and outer rings, when the force applied by the shaft to the inner ring is too small, the force applied by the inner ring to the rolling elements (balls or cylinders) is also very small. The frictional resistance between the inner ring and the rolling elements is insufficient to overcome the inherent frictional resistance of the rolling elements, thus the rotating inner ring cannot drive the rolling elements to roll together. Therefore, high-speed relative frictional motion is formed between the high-speed rotating inner ring and the contacting rolling elements, significantly increasing the rapid wear at the contact points between the inner ring and the rolling elements. Furthermore, because there is a set oil film gap between the inner ring and the rolling elements, when the inner ring rubs against the rolling elements on one side, all the rolling elements on the other side do not come into contact with the inner ring. And because the rolling elements being rubbed do not roll within the grooves of the outer ring, this leads to the following situations:

[0004] 1. Because the rolling element subjected to friction does not roll in the groove of the outer ring, the friction part with the inner ring cannot obtain new lubricating oil, which not only aggravates the wear of the friction part of the rolling element, but also aggravates the wear of the inner ring.

[0005] 2. Because the rolling element subjected to friction does not roll within the groove of the outer ring, only the fixed part of the rolling element subjected to friction is worn, its circumference is damaged, and it loses its rolling performance.

[0006] Hollow shaft motors have front and rear bearings within the motor shaft. During no-load testing at the manufacturer, the motor shaft is unloaded, and its own weight and the weight of the assembled rotor are generally sufficient to meet the minimum load requirements. However, in recent years, with the promotion of lightweighting requirements, motor shafts have been hollowed out, reducing the weight of the originally heavy motor shaft by about half. This causes the load on the front and rear bearings within the motor shaft to fall below the minimum load during no-load testing. If this problem is not resolved, the bearings will inevitably be damaged as described above during no-load testing. SUMMARY

[0007] The technical problem solved by the present application is how to solve the problem that the front end bearing and the rear end bearing built in the motor shaft of a hollow shaft motor cannot meet the minimum load during idling test.

[0008] To solve the above problems, the technical solution provided by the present application is:

[0009] A test loading mechanism for a hollow shaft motor, comprising an extension shaft fixedly connected with the outer end of the motor shaft, and a torque device for applying downward pressure to the motor shaft through the extension shaft, a support force point and a downward pressure point are respectively arranged at the front end and the rear end of the extension shaft, the torque device respectively provides upward support force F0 and downward pressure F1 to the support force point and the downward pressure point, the size of the support force F0 and the downward pressure F1 and the ratio between them are adjusted, so that the front end bearing and the rear end bearing of the motor shaft in the motor all bear a load exceeding the minimum load.

[0010] Support bearings and downward pressure bearings are respectively arranged at the support force point and the downward pressure point of the extension shaft, the support force F0 applied by the torque device to the support force point and the downward pressure F1 applied to the downward pressure point are respectively applied to the support bearings and the downward pressure bearings.

[0011] The torque device is arranged below the extension shaft, and comprises a support and a lever, the lever is parallel to the extension shaft, the front section of the lever is a support arm, and the rear section is a downward pressure arm, a support assembly capable of upwardly acting on the bottom of the support bearing is arranged at the front end of the support arm, and a downward pressure assembly capable of downwardly acting on the top of the downward pressure bearing is arranged at the rear end of the downward pressure arm, the support assembly can slide forward or backward on the support arm.

[0012] The support assembly and the downward pressure assembly both have elastic members, the support assembly applies the support force F0 to the support bearing through the elastic members, and the downward pressure bearing applies the downward pressure F1 to the downward pressure bearing through the elastic members.

[0013] The elastic members are compression springs.

[0014] The support assembly further comprises an upper seat body and a lower seat body, the upper seat body is used to abut against the bottom of the support bearing, the lower seat body is pressed on the support arm, and the compression spring is located between the upper seat body and the lower seat body, the lower seat body is provided with a downwardly opened sliding groove, the sliding groove is sleeved on the support arm and can slide forward and backward on the support arm.

[0015] The lower pressing assembly further comprises an upper seat body II and a lower pulling piece, the upper seat body II is pressed on the upper part of the lower pressing bearing, the lower pulling piece comprises a downwardly open inverted U-shaped lower pulling frame and a hanging column transversely passing through the rear end of the lower pressing arm, the lower pulling frame comprises a top plate, a lower pulling plate I and a lower pulling plate II which are vertically fixed at both ends of the top plate, the lower ends of the lower pulling plate I and the lower pulling plate II are respectively provided with hanging holes, in use, the lower pulling frame straddles the extension shaft, the hanging holes at the lower ends of the lower pulling plate I and the lower pulling plate II are respectively sleeved on both ends of the hanging column, the upper seat body II and the pressing bearing are located in the lower pulling frame, and the extension pressing spring is pressed between the top plate and the upper seat body II.

[0016] The loading hanging piece is hung on the rear end of the lower pressing arm, and the counterweight is placed on the loading hanging piece.

[0017] The loading hanging piece has a hanging rod, the lower end of the hanging rod has a bottom supporting plate, and the counterweight is placed on the bottom supporting plate.

[0018] The mounting position of the supporting bearing on the extension shaft can be shifted with the position change of the supporting assembly on the lever. Advantages

[0019] 1. The balanced increase of the load of the front end bearing and the rear end bearing enables the rolling unit to rotate with the rotation of the motor shaft, the friction between the rolling unit and the inner ring and the outer ring is rolling friction, the occurrence of sliding friction is avoided, and the front end bearing and the rear end bearing in the hollow shaft motor test process are not damaged;

[0020] 2. The structure is simple and reasonable, and very easy to operate;

[0021] 3. It can be suitable for motor test of different specifications. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A perspective view of the loading mechanism in use;

[0023] Figure 2 A perspective view of the extension shaft;

[0024] Figure 3 A perspective view of the torque device with the loading hanging piece;

[0025] Figure 4 A perspective view of the supporting assembly;

[0026] Figure 5 A perspective view of the lower pressing assembly;

[0027] Figure 6 A perspective view of the loading hanging piece;

[0028] Figure 7is a cross-sectional view of the hollow shaft motor;

[0029] Figure 8 is a cross-sectional view of the hollow shaft motor fixed butt joint extension shaft;

[0030] Figure 9 is a test schematic diagram for obtaining real support force F0 and pressing force F1;

[0031] In the figure: 100, motor; 110, rotor; 1, support; 101, horizontal support shaft; 2, lever; 201, support arm; 202, pressing arm; 3, support assembly; 301, upper seat body one; 3011, arc-shaped groove one; 302, lower seat body; 3021, sliding groove; 4, pressing assembly; 401, upper seat body two; 4011, arc-shaped groove two; 402, pull-down frame; 4021, top plate; 4022, pull-down plate one; 4023, pull-down plate two; 4020, hanging hole; 5, loading hanging piece; 501, hanging rod; 502, bottom support plate; 6, hanging column; 7, compression spring; 8, counterweight; 9, whole shaft; 901, motor shaft; 902, extension shaft; 10, front end bearing; 11, rear end bearing; 12, support bearing; 13, pressing bearing; 14, support frame; 15, pressure sensor one; 16, pressure sensor two. DETAILED DESCRIPTION

[0032] As Figure 7 shown, the motor 100 involved in the present application is generally a medium or large motor, the motor shaft 901 is relatively short outside the motor 100, and the outer end portion has various connection structures such as flanges, external splines, end teeth, etc. connected with other machine shafts, and the present application involves that the outer end surface of the motor shaft 901 has end teeth and axially arranged threaded connection holes.

[0033] Figure 7 As shown, the present application involves a cross-sectional view of the hollow shaft motor, the motor shaft 901 has a front end bearing 10 and a rear end bearing 11 inside the motor 100, and the rotor 110 is installed on the motor shaft 901 between the front end bearing 10 and the rear end bearing 11.

[0034] The present application will be further described below in combination with examples and drawings: Example One

[0035] As Figure 1 , 7,8 shows a hollow shaft motor test loading mechanism, including the extension shaft 902 fixed to the outer end of the motor shaft 901, and the torque device for applying downward pressure to the motor shaft 901 through the extension shaft 902, the support force point and the downward force point are arranged at the front end and the rear end of the extension shaft 902 respectively, the torque device provides upward support force F0 and downward pressure F1 to the support force point and the downward force point respectively, the size of the support force F0 and the downward pressure F1 and the ratio between them are adjusted, so that the front end bearing 10 and the rear end bearing 11 of the motor shaft 901 in the motor 100 can bear the load exceeding the minimum load. Because the length of the motor shaft 901 outside the motor 100 is short, the motor shaft needs to be rigidly extended, so the extension shaft 902 is fixed to the outer end of the motor shaft 901, so that the motor shaft 901 and the extension shaft 902 become a rigid whole shaft 9. According to the principle of lever, the upward support force F0 is applied to the front end of the extension shaft 902, which actually makes the front end of the whole shaft 9 become a fulcrum, and the whole shaft 9 becomes an arm that can rotate around the fulcrum. When we apply downward pressure F1 to the rear end of the extension shaft 902, the motor shaft 901 of the rear segment of the whole shaft 9 obtains the force of downward rotation, so that the motor shaft 901 in the motor 100 can obtain downward pressure F01 and F02 respectively. Obviously, whether the size of the pressure F01 and F02 can meet the requirements of loading depends on the size of the support force F0 and the downward pressure F1 and the ratio between them, especially when the test requires that the pressure F01 and F02 be equal or close, the size of the support force F0 and the downward pressure F1 needs to have a suitable ratio. If the support force F0 is too large, the load of the front end bearing 10 will be reduced, and the weight originally borne by the front end bearing 10 will be transferred to the front end of the extension shaft 902 and the rear end bearing 11; if the support force F0 is too small, the downward pressure F1 applied to the rear end of the extension shaft 902 will make the rear end of the motor shaft 901 rise, and the load of the rear end bearing 11 will be reduced.

[0036] To meet the size requirements of the support force F0 and the downward pressure F1 and the requirement of having a suitable ratio, the present application provides a simplest method, see example two and the attached Figure 9 As shown in the figure. In this way, we balance the load of the front end bearing 10 and the rear end bearing 11 by increasing the torque of the motor shaft 901 outside the motor 100 through the mechanism, so that the rolling unit can rotate with the rotation of the motor shaft 901, the friction between the rolling unit and the inner ring and the outer ring is rolling friction, which avoids the occurrence of sliding friction, and ensures that the front end bearing 10 and the rear end bearing 11 are not damaged during the test of the hollow shaft motor.

[0037] As Figure 1 , 2As shown, the support bearing 12 and the pressing bearing 13 are respectively arranged at the support force point and the pressing force point of the extension shaft 902, and the support force F0 exerted by the torque device on the support force point and the pressing force F1 exerted by the torque device on the pressing force point are respectively applied to the support bearing 12 and the pressing bearing 13. In this way, when the extension shaft 902 is subjected to the action force, the high-speed rotation of the extension shaft 902 along with the motor shaft 901 is not affected.

[0038] As shown in FIGS. Figure 1 , 3 The torque device is arranged below the extension shaft 902, and includes a support 1 and a lever 2. The support 1 is preferably provided with a horizontal support shaft 101, and the lever 2 is installed on the horizontal support shaft 101 to rotate around the horizontal support shaft 101 as the fulcrum. The lever 2 is parallel to the extension shaft 902, and the front section of the lever 2 is a support arm 201, and the rear section is a pressing arm 202. The support arm 201 is provided with a support assembly 3 at the front end, which can act upward on the bottom of the support bearing 12. The pressing arm 202 is provided with a pressing assembly 4 at the rear end, which can act downward on the top of the pressing bearing. The support assembly 3 can slide forward or backward on the support arm 201. In this way, the lever 2, the support assembly 3 and the pressing assembly 4 apply action force to the extension shaft 902, which can simultaneously provide the support force F0 and the pressing force F1, and by sliding the support assembly 3 forward or backward on the support arm 201, the effective length of the support arm 201 is actually changed, that is, the torque ratio of the support force F0 multiplied by the effective length of the support arm 201 and the pressing force F1 multiplied by the length of the pressing arm 202 is changed, so that the size ratio of the support force F0 and the pressing force F1 can be easily adjusted.

[0039] It should be noted that the installation position of the support bearing 12 on the extension shaft 902 can be shifted according to the position of the support assembly 3 on the lever 2. Of course, the installation position of the support bearing 12 on the extension shaft 902 is preferably the accurate installation position obtained by prior pretest.

[0040] As shown in FIGS. Figure 1 , 3 , 4, 5, the support assembly 3 and the pressing assembly 4 both have elastic members. The support assembly 3 applies the support force F0 to the support bearing 12 through the elastic member, and the pressing assembly 4 applies the pressing force F1 to the pressing bearing through the elastic member. Since it is difficult to accurately set the height of the support 1 in the torque device, if the elastic members are not provided, only one of the support assembly 3 and the pressing assembly 4 can contact the extension shaft 902, and the other cannot contact the extension shaft 902, so that the action force cannot be applied. Therefore, the extension assembly can automatically adjust the force relationship of all related force receiving parts including the support assembly 3, the pressing assembly 4, and the front end bearing 10 and the rear end bearing 11.

[0041] As a preference, the elastic member is a compression spring 7 with a long compression stroke and easy to set the compression stroke, but it can also be a rubber body.

[0042] As shown in Figure 1 , 4 The support assembly 3 further comprises an upper seat body 301 for pressing against the bottom of the support bearing 12 and a lower seat body 302 for pressing against the support arm 201, and the compression spring 7 is located between the upper seat body 301 and the lower seat body 302; the lower seat body 302 is provided with a downwardly open sliding groove 3021 which is sleeved on the support arm 201 and can slide forward and backward on the support arm 201. In order to facilitate stable contact with the support bearing 12, the upper seat body 301 is provided with an upwardly open arc-shaped groove 3011 with an arc consistent with the arc of the outer ring of the support bearing 12.

[0043] As shown in Figure 1 , 5 The lower pressing assembly 4 further comprises an upper seat body 401 for pressing against the upper part of the lower pressing bearing 13 and a lower pulling member, the lower pulling member comprises a downwardly open inverted U-shaped lower pulling frame 402 and a hanging column 6 transversely passing through the rear end of the lower pressing arm 202, the lower pulling frame 402 comprises a top plate 4021, lower pulling plates one 4022 and two 4023 vertically suspended and fixed at both ends of the top plate 4021, and the lower ends of the lower pulling plates one 4022 and two 4023 are respectively provided with hanging holes 4020, in use, the lower pulling frame 402 straddles the extension shaft 902, the hanging holes 4020 at the lower ends of the lower pulling plates one 4022 and two 4023 are respectively sleeved on both ends of the hanging column 6, the upper seat body 401 and the pressing bearing are located within the lower pulling frame 402, and the compression spring 7 is compressed between the top plate 4021 and the upper seat body 401. In this way, the lower pressing arm 202 exerts a downward force on the lower pulling frame 402, which can exert a downward force on the lower pressing bearing 13 through the compression spring 7 and the upper seat body 401. In order to facilitate stable contact with the lower pressing bearing 13, the upper seat body 401 is provided with an arc-shaped groove 4011 with an arc consistent with the arc of the outer ring of the lower pressing bearing 13.

[0044] As shown in Figure 1 , 6 It further comprises a loading hanging member 5 and a counterweight 8, the loading hanging member 5 is hung at the rear end of the lower pressing arm 202, and the counterweight 8 is placed on the loading hanging member 5. There can be multiple counterweights 8, and they can also have different weights.

[0045] The loading hanging member 5 has a hanging rod 501, and the lower end of the hanging rod has a bottom supporting plate 502, on which the counterweight 8 is placed. Embodiment two

[0046] As shown in Figure 9As shown, a method for obtaining the qualified support force F0 and the pressing force F1 and the appropriate ratio between the two in embodiment one includes installation and testing.

[0047] Installation: complete the assembly of the front end bearing 10, the rear end bearing 11 and the rotor 110 or the alternative on the motor shaft 901; complete the fixed butt joint of the extension shaft 902 on the motor shaft 901; set the support frame 14 capable of supporting the front end bearing 10 and the rear end bearing 11, so that the front end bearing 10 and the rear end bearing 11 assembled on the motor shaft 901 are placed on the support frame 14, and the pressure sensor one 15 and the pressure sensor two 16 are arranged between the front end bearing 10 and the support frame 14 and between the rear end bearing 11 and the support frame 14 respectively, at this time, the pressure sensor one 15 and the rear pressure sensor two 16 both have the weight value of the rotor 110 and the motor shaft 901.

[0048] Testing: the support force F0 and the pressing force F1 are respectively applied to the support stress point and the pressing stress point of the extension shaft 902, the pressure values F01, F02 are read from the pressure sensor one 15 and the pressure sensor two 16, the size of the support force F0 is increased or decreased so that F01, F02 are equal or close to equal. At the same time, the support force F0 and the pressing force F1 are increased or decreased so that F01, F02 are equal or close to equal, and the pressure F01 received by the front end bearing 10 and the pressure F02 received by the rear end bearing 11 are both greater than the inherent minimum load, the size of the support force F0 and the pressing force F1 are recorded, so that the qualified support force F0 and the pressing force F1 and the appropriate ratio between the two are obtained.

[0049] After the use of the torque device, the qualified support force F0 and the pressing force F1 and the appropriate ratio between the two can be easily obtained by sliding the support assembly 3 and adding or reducing the counterweight 8, see Figure 1 .

[0050] The above embodiments are only used to more clearly describe the present application and cannot be considered as limiting the protection scope covered by the present application, and any equivalent form of modification shall be considered as falling within the protection scope covered by the present application.

Claims

1. A hollow shaft motor test loading mechanism, characterized in that: The device includes an extension shaft (902) fixedly connected to the outer end of the motor shaft (901), and a torque device that applies downward pressure to the motor shaft (901) through the extension shaft (902). Support points and downward pressure points are respectively set at the front and rear ends of the extension shaft (902). The torque device provides an upward support force F0 and a downward pressure force F1 to the support points and the downward pressure points respectively. By adjusting the magnitude of the support force F0 and the downward pressure force F1 and the ratio between them, the front bearing (10) and the rear bearing (11) of the motor shaft (901) within the motor (100) both bear loads exceeding the minimum load. The torque device is located below the extension shaft (902) and includes a support (1) and a lever (2). The lever (2) is parallel to the extension shaft (902). The lever (2) has a support arm (201) at the front and a pressure arm (202) at the rear. The support arm (201) has a support component (3) that can act upward on the bottom of the support bearing (12), and the pressure arm (202) has a pressure component (4) that can act downward on the top of the pressure bearing (13). The support component (3) can slide forward or backward on the support arm (201). The lever (201) also includes a loading hanger (5) and a counterweight (8). The loading hanger (5) is suspended at the rear end of the pressure arm (202), and the counterweight (8) is placed on the loading hanger (5). The loading hanger (5) has a hanging rod (501) and a bottom support plate (502) at the lower end of the hanging rod. The counterweight (8) is placed on the bottom support plate (502).

2. The hollow shaft motor test loading mechanism according to claim 1, characterized in that: Support bearing (12) and pressure bearing (13) are provided at the support force point and the pressure force point of the extension shaft (902), respectively. The support force F0 applied by the torque device to the support force point and the pressure force F1 applied to the pressure force point act on the support bearing (12) and the pressure bearing (13), respectively.

3. The hollow shaft motor test loading mechanism according to claim 2, characterized in that: Both the support assembly (3) and the pressing assembly (4) have elastic elements. The support assembly (3) applies a supporting force F0 to the support bearing (12) through the elastic element, and the pressing bearing (13) applies a downward force F1 to the pressing bearing (13) through the elastic element.

4. The hollow shaft motor test loading mechanism according to claim 3, characterized in that: The elastic element is a compression spring (7).

5. The hollow shaft motor test loading mechanism according to claim 4, characterized in that: The support assembly (3) further includes an upper seat (301) and a lower seat (302). The upper seat (301) is used to hold the bottom of the support bearing (12), and the lower seat (302) presses on the support arm (201). The compression spring (7) is located between the upper seat (301) and the lower seat (302). The lower seat (302) is provided with a downward-opening groove (3021). The groove (3021) is fitted on the support arm (201) and can slide back and forth on the support arm (201).

6. The hollow shaft motor test loading mechanism according to claim 4, characterized in that: The pressing assembly (4) further includes an upper seat (401) and a pull-down member. The upper seat (401) presses against the upper part of the pressing bearing (13). The pull-down member includes an inverted U-shaped pull-down frame (402) with its opening facing downward and a hanging column (6) that passes through the rear end of the pressing arm (202). The pull-down frame (402) includes a top plate (4021), a pull-down plate one (4022) and a pull-down plate two (4023) that are suspended and fixed at both ends of the top plate (4021). The pull-down plate one (4022) The lower ends of the first pull-down plate (4022) and the second pull-down plate (4023) are respectively provided with hanging holes (4020). When in use, the pull-down frame (402) straddles the extension shaft (902), and the hanging holes (4020) at the lower ends of the first pull-down plate (4022) and the second pull-down plate (4023) are respectively fitted onto the two ends of the hanging column (6). The second upper seat (401) and the lower pressure bearing (13) are located inside the pull-down frame (402), and the compression spring (7) is pressed between the top plate (4021) and the second upper seat (401).

7. The hollow shaft motor test loading mechanism according to claim 1, characterized in that: The mounting position of the support bearing (12) on the extension shaft (902) can be shifted as the position of the support assembly (3) on the lever (2) changes.

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